Hydraulic jar



D. D. WEBB HYDRAULIC JAR Nov. 2, 1965 2 Sheets-Sheet 1 Filed Oct. 1,1963 u W ZZZ INVENTOR DERREL D. WEBB ATTORNEY 0. D. WEBB HYDRAULIC JARNov. 2, 1965 2 Sheets-Sheet 2 Filed Oct. 1, 1963 INVENTOR DERREL D. WEBBATTORNEY United States Patent Office 3,215,211 Patented Nov. 2, 19653,215,211 HYDRAULIC JAR Derrel B. Webb, Houston, Tex., assignor toHouston Engineers, lnc., Houston, Tern, a corporation of Texas FiledOct. 1, 1963, Ser. No. 312,949 Claims. (Cl. 175296) This inventionrelates to well apparatus and more particularly to a hydraulic jardesigned to impart an impact to well tools or other objects lodged in awell beore for the purpose of removing the same and also contemplates adevice which will operate substantially independently of externalpressur s or temperatures.

As is well known, broken drills, broken sections of pipe and otherobjects occasionally become lodged in the bore of a well during drillingoperations and when this occurs, drilling operations must be suspendeduntil the objects have been removed. This often requires long andtedious fishing operations and in order to facilitate the removal ofsuch objects, it has heretofore been proposed to utilize various typesof jarring mechanisms to impart an impact to the objects lodged in thewell bore in order to free the same and such jarring mechanisms havealso included those of the so-called hydraulic type in which a fluid isutilized to facilitate building up a force or tension in a pipe string,Wire line or the like, which when released, imparts an upward impact tothe objects lodged in a well bore in order to free the same.

It is accordingly an object of the present invention to provide ahydraulic jar which may be suspended in a well on the end of a wire lineand is designed to deliver an impact only in one direction.

A further object of the invention is the provision of a hydraulic jarwhich is relatively simple in construction embodying only fourrelatively movable parts thereby reducing the cost of manufacture andproviding a long wearing dependable device.

A still further object of the invention is the provision of a hydraulicjar designed to deliver an impact in one direction only and which may berapidly and conveniently reset for delivering a further impact, suchresetting operation being entirely free of impact in the oppositedirection to that desired Another object of the invention is theprovision of a hydraulic jar utilizing a closed fluid chamber filledwith a hydraulic working fluid and in which means is provided foradjusting for differences in pressure and temperature between thechamber and the exterior of the device thereby maintaining the operationof such device substantially independent of such differences in pressureor temperature.

Further objects and advantages of the invention will be apparent fromthe following description taken in conjunction with the accompanyingdrawings wherein:

FIG. 1 is a longitudinal sectional view showing a hydraulic jarconstructed in accordance with this invention;

FIG. 2 is a sectional view taken substantially on the line 22 of FIG. 1;

FIG. 3 is a secional view taken substantially on the line 33 of FIG. 1;

FIG. 4 is a fragmentary longitudinal sectional view showing therelationship between the piston and valve sleeve prior to delivering animpact; and

FIG. 5 is a longitudinal sectional view similar to FIG. 4, but showingthe relative position between the piston and valve sleeve at one pointduring the resetting operation.

With continued reference to the drawings, there is shown a hydraulic jarconstructed in accordance with this invention and comprising anelongated hollow cylinder body which is of a suflicient length toprovide for adequate travel of the parts received therein and also forcontaining an adequate quantity of hydraulic working fluid. Secured tothe upper end of the cylinder body 10 is a gland 11 having a bore 12extending therethrough and the gland 11 may be removably secured to thecylinder body 10 by screw threaded means 13 and a suitable packing means14 is provided for preventing leakage of fluid from the interior of thecylinder body 10. It is to be noted that a portion 15 of the bore 12 issomewhat enlarged and the purpose thereof will be later described. Thelower end 16 of the gland 11 forms a shoulder within the cylinder body10 to provide an anvil, the function of which will be later described.

An elongated valve sleeve 25 is slidably received in bore 12 of thegland 11 and projects downwardly into the cylinder body 10 andterminates at the lower end in a piston 18 disposed in the chamber 19provided by the cylinder body 10. Packing means 40 is provided in thegland 11 engaging the surface of mandrel 17 to prevent leakage of fluidfrom the chamber 19 and furthermore, wiping means 20 is provided in thegland 11 engaging the surface of mandrel 17 to wipe fluid and foreignmaterial therefrom, thereby reducing wear during operation of theapparatus.

A suitable coupling means 21 is removably secured by screw threadedmeans 22 to the upper end of the mandrel 17 and the coupling means 21 islocked against removal from the mandrel 17 by a suitable set screw 23.The upper end of the coupling means 21 is provided with screw threadedcoupling means 24 for attaching the same to a complementary couplingmeans on a wire line from which the device of this invention issuspended.

An elongated value sleeve 25 is slidably received in the chamber 19 ofthe cylinder body 10 and the valve sleeve 25 surrounds the piston 18 andis provided at the lower end thereof with an inwardly extending radialflange 26. As clearly shown in FIGS. 1 and 3, the valve sleeve 25 isprovided with by-pass slots 27 in the wall thereof extending between theflange 26 and a point 28 substantially intermediate the length of thesleeve 25. It is to be noted that the clearance between the sleeve 25and the outer surface of the piston 18 and between the outer surface ofthe sleeve 25 and the inner surface of the cylinder body 10 issufl'icient to permit limited flow of fluid therebetween duringoperation of the device and the significance of this fluid flow willlater appear during a description of the operation of the device.

Below the valve sleeve 25 is a packing member 29 which is slidablyreceived in the chamber 19 of the cylinder body 10 and suitable packingmeans 30 is provided on said packing member 29 for engaging the innerwall of the cylinder body 10.

A lower coupling means 31 is removably secured to the lower end of thecylinder body 10 by screw threaded means or the like 32 and the coupling31 is provided at the lower end with a threaded socket 33 for attachingfishing or other tools to the device. The lower coupling 31 is alsoprovided with a longitudinal passage 34 communicating with the lower endof the chamber 19 in the cylinder body 10 and the passage 34 in turncommunicates with radial passages 35 which are open to the exterior ofthe device.

The upper end 36 of the psiton 18 provides a hammer surface whichcooperates with the anvil 16 on the lower end of the gland 11.

In order to facilitate movement of the piston 18 into the upper end ofthe valve sleeve 25, such upper end may be tapered or flared as shown at37.

The chamber 19 of the cylinder body 19 may be filled with a suitablehydraulic operating fluid by assembling the tool except for packingmember 29 and lower coupling'member 31 and then inverting the tool andfilling with the hydraulic fluid. Packing member 29 is then =1) placedin proper position and lower coupling 31 is partially threaded intocylinder body at threads 32. The tool is then turned over and screwthreaded plug 39 in opening 38 is removed. Lower coupling 31 is nowcompletely threaded into cylinder body 10, thus permitting any air orexcess oil to be discharged through enlarged portion of the bore 12 andout through opening 38, at which time screw threaded plug 39 isreplaced.

In operating the device of this invention, the chamber 19 in thecylinder body 10 has been filled with suitable hydraulic fluid and afishing tool is attached to the lower coupling means 31 while the uppercoupling means 21 is attached to a wire line and weight bars, not shown.The device is then lowered into the well and the fishing tool engagedwith the object to be removed from the well. Upon exerting an upwardpull on the wire line, the mandrel 17 and piston 18 move upward withinthe valve sleeve 25, and since this operates to create a hydraulicpressure above the sleeve 25, such pressure will exert a downward forceon the upper surface of sleeve 25 thereby tending to hold such sleeve incontact with packing member 29. At the same time differential pressureswill be exerted on packing member 29 due to the tendency to create avoid caused by the upward movement of mandrel 17 out of chamber 19 andfrom hydrostatic well pressures below packing member 29. When suflicientdifferential pressures are exerted, packing member 29 will move upwardas the mandrel 17 and piston 18 move upward in sleeve 25, thus raisingsleeve 25 off its lowermost position. Since the volumetric displacementof packing member 29 is much greater than the volumetric displacementcreated by withdrawal of mandrel 17 from the fluid chamber 19, thisupward movement of packing member 29 and sleeve 25 will be much lessthan the upward movement of the mandrel 17 and piston 18. During thisupward movement of piston 13, there will be a slight leakage ofhydraulic fluid between the piston 18 and sleeve 25 and between sleeve25 and the inner surface of cylinder body 10. Since the hydraulic fluidabove piston 18 in chamber 19 is substantially incompressible, the wireline will stretch thereby storing energy therein, but upward movement ofpiston 18 will be permitted. When the lower end of piston 18 reaches apoint in the upper end of valve sleeve 25, there will be a sudden flowof fluid from above the piston 18 to beneath the same, therebypermitting sudden upward movement of piston 18 and this sudden upwardmovement of piston 18 will result in striking of the upper hammersurface 36 of the piston 18 on the anvil 16 of gland 11 therebyproviding an impact which is transmitted through the cylinder body 10and the lower coupling member 31 to the object in the well engaged bythe fishing tool thereby tending to dislodge such stuck object.

Thereafter the wire line and weight bars are lowered which permitsdownward movement of the mandrel 17 and piston 18 in the chamber 19 andsince the majority of the fluid in the chamber 19 is now below thepiston 18, there will be created a pressure tending to move packingmember 29 downward and at the same time to force valve sleeve 25upwardly and such upward movement of sleeve 25 and downward movement ofpiston 18 and packing member 29 will continue until the upper end of thepiston 18 moves below the upper ends 28 of the by-pass slots 27 in thesleeve 25 thereby permitting flow of fluid from below piston 18 throughthe by-pass slots 27 to the space in the chamber 19 above the piston 18,at which time the piston 18, valve sleeve 25 and packing member 29 willresume the relative positions shown in FIG. 1 and the device is now incondition for a further impact or jarring operation.

From the foregoing, it can be seen that packing member 29 not onlyprovides a division between the clean operating fluid required inchamber 19 and the well fluid that may be found in well bores, but alsooperates to correct unequal pressure tendencies both internally andexternally so as to permit automatic adjustments in the restrictive andfree travel relationship of piston 18 and sleeve 25, thereby enablingthe jar to deliver impact blows over a long period of time and in wellbores of great depths and pressures.

It will be obvious that by the above described invention there has beenprovided a relatively simple, yet highly effective hydraulic jar whichmay be utilized at the end of a wire line to dislodge objects from awell and which will maintain operating efliciency over a relatively longperiod of time regardless of pressure or temperature conditionsencountered in the well.

It will be obvious to those skilled in the art that various changes maybe made in the invention without departing from the spirit and scopethereof and therefore the invention is not limited by that which isshown in the drawings and described in the specification, but only asindicated in the appended claims.

What is claimed is:

1. A uni-directional hydraulic jar comprising a hollow elongatedcylinder body, means providing an anvil carried by said body, anelongated mandrel slidably received in said body, the space within saidbody providing a fluid receiving chamber, packing means in the upperpart of said body engaging said mandrel, coupling means on the upper endof said mandrel for attaching the same to a line or fishing string, apiston on the lower end of said mandrel disposed in said chamber, meanson said piston providing a hammer surface for striking said anvil uponcompletion of upward movement of said mandrel with respect to said body,a sleeve slidably received in said body, an inwardly extending flange atthe lower end of said sleeve, by-pass slots in the wall of said sleeveextending between said flange and a point intermediate the length ofsaid sleeve, said sleeve slidably receiving said piston, a clearancespace between said sleeve and said body and between said sleeve and saidpiston, said sleeve providing a valve cooperating with said pistonduring a portion of the travel of said piston to restrict liquid flow inone direction to said clearance spaces and during another portion ofpiston travel to permit substantially unrestricted flow of liquid in theopposite direction, a packing member slidably received in said bodybelow said sleeve, packing means on said packing member engaging theinner wall of said body and a coupling means secured to the lower end ofsaid body for attaching the same to a tool, said last named couplingmeans having a passage communicating with the interior of said bodybelow said packing member and with the exterior of said last namedcoupling member to permit the flow of well fluid into and out of saidbody below said packing member, the aforesaid combination of elementsconstituting means to move said packing member upwardly or downwardly insaid body when said piston is moved to adjust the restrictive and freetravel relationship of said piston and sleeve and to maintainsubstantial pressure equilibrium between the interior of said body abovesaid packing member and the exterior of said body.

2. A uni-directional hydraulic jar comprising a hollow elongatedcylinder body, means providing an anvil carried by said body, anelongated mandrel slidably received in said body, the space within saidbody providing a fluid receiving chamber, packing means in the upperpart of said body engaging said mandrel, coupling means on the upper endof said mandrel for attaching the same to a line or fishing string, apiston on the lower end of said mandrel disposed in said chamber, meanson said piston providing a hammer surface for striking said anvil uponcompletion of upper movement of said mandrel with respect to said body,a sleeve slidably received in said body, an inwardly extending flange atthe lower end of said sleeve, by-pass slots in the wall of said sleeveextending between said flange and a point intermediate the length ofsaid sleeve, said sleeve slidably receiving said piston, a clearancespace between said sleeve and said body and between said sleeve and saidpiston, said sleeve providing a valve cooperating with said pistonduring a portion of the travel of said piston to restrict liquid flow inone direction to said clearance spaces and during another portion ofpiston travel to permit substantially unretricted flow of liquid in theopposite direction, a packing member slidably received in said bodybelow said sleeve and a coupling means secured to the lower end of saidbody for attaching the same to a tool, said last named coupling meanshaving a passage communicating with the interior of said body below saidpacking member and with the exterior of said last named coupling memberto permit the flow of well fluid into and out of said body below saidpacking member, the aforesaid combination of elements constituting meansto move said packing member upwardly or downwardly in said body whensaid piston is moved to adjust the restrictive and free travelrelationship of said piston and sleeve and to maintain substantialpressure equilibrium between the interior of said body above saidpacking member and the exterior of said body.

3. A uni-directional hydraulic jar comprising a hollow elongatedcylinder body, means providing an anvil carried by said body, anelongated mandrel slidably received in said body, the space within saidbody providing a fluid receiving chamber, packing means in the upper endof said body engaging said mandrel, coupling means on the upper end ofsaid mandrel for attaching the same to a line or fishing string, apiston on the lower end of said mandrel disposed in said chamber, meanson said piston providing a hammer surface for striking said anvil uponcompletion of upward movement of said mandrel with respect to said body,a sleeve slidably received in said body, inwardly extending means at thelower end of said sleeve, bypass slots in the wall of said sleeveextending between a point adjacent the lower end of said sleeve and apoint intermediate the length of said sleeve, said sleeve slidablyreceiving said piston, a clearance space between said sleeve and saidbody and between said sleeve and said piston, said sleeve providing avalve cooperating with said piston during a portion of the travel ofsaid piston to restrict liquid flow in one direction to said clearancespaces and during another portion of piston travel to permitsubstantially unrestricted flow of liquid in the opposite direction, asolid packing member having a diameter substantially equal to that ofsaid sleeve slidably received in said body below said sleeve and acoupling means secured to the lower end of said body for attaching thesame to a tool, said last named coupling means having a passagecomunicating with the interior of said body below said packing memberand with the exterior of said last named coupling member to permit theflow of well fluid into and out of said body below said packing member,whereby said packing member may move upwardly or downwardly in said bodyto adjust the restrictive and free travel relationship of said pistonand sleeve and to maintain substantial pressure equilibrium between theinterior of said body above said packing member and the exterior of saidbody.

4. A uni-directional hydraulic jar comprising a hollow elongatedcylinder body, means providing an anvil carried by said body, anelongated mandrel slidably received in said body, the space within saidbody providing a fluid receiving chamber, packing means in the upperpart of said body engaging said mandrel, coupling means on the upper endof said mandrel for attaching the same to a line or fishing string, apiston on the lower end of said mandrel disposed in said chamber, meanson said piston providing a hammer surface for striking said anvil uponcompletion of upward movement of said mandrel with respect to said body,a sleeve slidably received in said body, inwardly extending means at thelower end of said sleeve, by-pass slots in the wall of said sleeveextending between a point adjacent the lower end of said sleeve and apoint intermediate the length of said sleeve, said sleeve slidablyreceiving said piston, a clearance space between said sleeve and saidbody and between said sleeve and said piston, said sleeve providing avalve cooperating with said piston during a portion of the travel ofsaid piston to restrict liquid flow in one direction to said clearancespaces and during another portion of piston travel to permitsubstantially unrestricted flow of liquid in the opposite direction, apacking member slidably received in said body below said sleeve, acoupling means secured to the lower end of said body for attaching thesame to a tool and means providing communication between the interior ofsaid body below said packingmember and the exterior of said body topermit the flow of well fluid into and out of said body below saidpacking member, the aforesaid combination of elements constituting meansto move said packing member upwardly or downwardly in said body whensaid piston is moved to adjust the restrictive and free travelrelationship of said piston and sleeve and to maintain substantialpressure equilibrium between the interior of said body above saidpacking member and the exterior of said body.

5. A uni-directional hydraulic jar comprising a hollow elongatedcylinder body, means providing an avil carried by said body, anelongated mandrel slidably received in said body, the space within saidbody providing a fluid receiving chamber, packing means in the upperpart of said body engaging said mandrel, coupling means on the upper endof said mandrel for attaching the same to a line or fishing string, apiston on the lower end of said mandrel disposed in said chamber, meanson said piston providing a hammer surface for striking said anvil uponcompletion of upward movement of said mandrel with respect to said body,a sleeve slidably received in said body, means on said sleeve forengaging said piston, bypass slots in the wall of said sleeve extendingbetween a point adjacent the lower end of said sleeve and a pointintermediate the length of said sleeve, said sleeve slidably receivingsaid piston, a clearance space between said sleeve and said body andbetween said sleeve and said piston, said sleeve providing a valvecooperating with said piston during a portion of the travel of saidpiston to restrict liquid flow in one direction to said clearance spacesand during another portion of piston travel to permit substantiallyunrestricted flow of liquid in the opposite direction, a solid packingmember having a diameter substantially equal to that of said sleeveslidably received in said body below said sleeve, a coupling meanssecured to the lower end of said body for attaching the same to a tooland means providing communication between the interior of said bodybelow said packing member and the exterior of said body to permit theflow of well fluid into and out of said body below said packing member,whereby said packing member may move upwardly or downwardly in said bodyto adjust the restrictive and free travel relationship of said pistonand sleeve and to maintain substantial pressure equilibrium between theinterior of said body above said packing member and the exterior of saidbody.

References Cited by the Examiner UNITED STATES PATENTS 1,637,505 8/27Wigle -297 X 2,645,459 7/53 Sutliif 175297 2,802,703 8/57 Harrison175297 3,005,505 10/61 Webb 175297 CHARLES E. OCONNELL, PrimaryExaminer.

2. A UNI-DIRECTIONAL HYDRAULIC JAR COMPRISING A HOLLOW ENCLOSED CYLINDERBODY, MEANS PROVIDING AN ANVIL CARRIED BY SAID BODY, AN ELONGATEDMANDREL SLIDABLY RECEIVED IN SAID BODY, THE SPACE WITHIN SAID BODYPROVIDING A FLUID RECEIVING CHAMBER, PACKING MEANS IN THE UPPER PART OFSAID BODY ENGAGING SAID MANDREL, COUPLING MEANS ON THE UPPER END OF SAIDMANDREL FOR ATTACHING THE SAME TO A LINE OR FISHING STRING, A PISTON ONTHE LOWER END OF SAID MANDREL DISPOSED IN SAID CHAMBER, MEANS ON SAIDPISTON PROVIDING A HAMMER SURFACE FOR STRIKING SAID ANVIL UPONCOMPLETION OF UPPER MOVEMENT OF SAID MANDREL WITH RESPECT TO SAID BODY,A SLEEVE SLIDABLY RECEIVED IN SAID BODY, AN INWARDLY EXTENDING FLANGE ATTHE LOWER END OF SAID SLEEVE, BY-PASS SLOTS IN THE WALL OF SAID SLEEVEEXTENDING BETWEEN SAID FLANGE AND A POINT INTERMEDIATE THE LENGTH OFSAID SLEEVE, SAID SLEEVE SLIDABLY RECEIVING SAID PISTON, A CLEARANCESPACE BETWEEN SAID SLEEVE AND SAID BODY AND BETWEEN SAID SLEEVE AND SAIDPISTON, SAID SLEEVE PROVIDING A VALVE COOPERATING WITH SAID PISTONDURING A PORTION OF THE TRAVEL OF SAID PISTON TO RESTRICT LIQUID FLOW INONE DIRECTION TO SAID CLEARANCE SPACES AND DURING ANOTHER PORTION OFPISTON TRAVEL TO PERMIT SUBSTANTIALLY UNRESTRICTED FLOW OF LIQUID IN THEOPPOSITE DIRECTION, A PACKING MEMBER SLIDABLY RECEIVED IN SAID BODYBELOW SAID SLEEVE AND A COUPLING MEANS SECURED TO THE LOWER END OF SAIDBODY FOR ATTACHING THE SAME TO A TOOL, SAID LAST NAMED COUPLING MEANSHAVING A PASSAGE COMMUNICATING WITH THE INTERIOR OF SAID BODY BELOW SAIDPACKING MEMBER AND WITH THE EXTERIOR OF SAID LAST NAMED COUPLING MEMBERTO PERMIT THE FLOW OF WELL FLUID INTO AND OUT OF SAID BODY BELOW SAIDPACKING MEMBER, THE AFORESAID COMBINATION OF ELEMENTS CONSTITUTING MEANSTO MOVE SAID PACKING MEMBER UPWARDLY OR DOWNWARDLY IN SAID BODY WHENSAID PISTON IS MOVED TO ADJUST THE RESTRICTIVE AND FREE TRAVELRELATIONSHIP OF SAID PISTON AND SLEEVE AND TO MAINTAIN SUBSTANTIALPRESSURE EQUILIBRIUM BETWEEN TE INTERIOR OF SAID BODY ABOVE SAID PACKINGMEMBER AND THE EXTERIOR OF SAID BODY.